Table 2.

Characteristics of the 7 E. coli transformants representative of the strains presenting a reduced susceptibility to cefepime.

Isolate	Date	MIC (mg/L) in transformants					Mutations in the ampC sequence
		CAZa	FOX	FEP	IMI	XNL
REDUCED SUSCEPTIBILITY TO CEFEPIME
TF-15166	2006	48	24	2	0.25	16	H296P, A215V
TF-19023	2007	>256	32	4	0.25	32	H296P
TF-15816	2006	>256	64	8	0.38	128	S287N
TF-18991	2007	96	32	1	0.25	64	S287C, A215V
TF-25456	2010	16	>256	0.125	0.25	32	A215V
TF-16290	2006	32	34	0.38	0.125	16	A292V
TF-20098	2007	8	48	0.19	0.5	16	A89T, P194A, A220T, R232C
SUSCEPTIBLE CONTROLS
TF-15829	2006	24	>256	0.125	0.25	64	none
TOP 10	–	0.19	4	0.023	0.19	1	none

^aCAZ, ceftazidime; FOX, cefoxitin; FEP, cefepime; IMI, imipenem; XNL, ceftiofur.